1. Field of the Invention
The present invention relates to a toner-collecting device and an image forming apparatus.
2. Description of the Related Art
Image forming apparatuses, such as copiers, printers, facsimile machines, and multifunction product (MFP) that combines any or all of the functions of these, include a process unit. In the process unit system, a casing that houses an image carrier (photosensitive drum), a charger, a developing unit, or a process unit such as a toner-collecting unit can be detachably attached to a main body of the image forming apparatus. By using the process unit system, a user can easily replace the process unit at the time of maintenance.
Japanese Patent Application Laid-open No. 2006-98743 discloses a conventional image forming apparatus that includes a process unit including an image carrier and a toner-collecting unit. The toner-collecting unit contains waste toner that remains after an image is created. Conveying screws for conveying waste toner are fixedly set inside the toner-collecting unit. Waste toner is brought in from an opening of the toner-collecting unit and stirred by the conveying screws. With this configuration, the toner-collecting unit can be effectively filled with waste toner.
An outer wall that forms the toner-collecting unit is formed of two segmented casings. Upon manufacture of the toner-collecting unit, matching surfaces of the casings are ultrasonically welded such that toner does not leak out from between the matching surfaces.
However, in the process of manufacturing the toner-collecting unit that internally includes the conveying screws as described above, if both the casings are welded after the conveying screws are inserted in the casings, end portions of the conveying screws protruding from the casings come in the way to hold the casings by using a welding horn. Accordingly, the conveying screws need to be inserted in the casings after the casings are welded.
Insertion of shaft members such as conveying screws from one end of the casings to the other end is difficult after the casings are welded. This decreases manufacturing efficiency.